import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.stream.Stream;

public class No00000191_Main {

	public static void main(String[] args) throws IOException {

		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

		int n = Integer.parseInt(br.readLine());

		int[] intArr = Stream.of(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
		int line = Arrays.stream(intArr).sum() / 10;
		int cnt = 0;
		for(int i = 1; i < n; i++) {
			if(line >= intArr[i] ) {
				cnt++;
			}
		}
		System.out.println(cnt * 30);
	}
}